Background Previous studies reported a reduction in cardiac catheterization laboratory activations for ST-Elevation Myocardial Infarctions in the US1 and Spain2 during the early COVID-19 pandemic. We analyzed the long-term relationship between regional COVID burden and acute myocardial infarction (AMI) incidence across the US.

Methods Monthly ACS data was drawn from the de-identified Vizient database of clinical data. Patients diagnosed with AMI (defined by ICD-10 code I.21) were drawn from 20 US hospital systems from January 2019 to June 2023. COVID-19 data were drawn from the de-identified New York Times github database of COVID-19 data. Monthly positive COVID-19 cases were drawn at the state level and then grouped within the West, Midwestern, Northeastern, Mid-Atlantic, and Southern regions. March 1, 2020 was identified as the beginning of the “after COVID” (AC) period and any prior data were identified as the “before COVID” (BC) period (January 2019 to February 2020). Spearman’s ρ assessed the association between statewide COVID-19 cases and AMI diagnoses, and was repeated with a one-month delay applied to AMI diagnoses to account for the potential lag time between COVID-19 burden and corresponding behavioral modifications. A mixed linear model with random intercepts corrected for time as a continuous variable estimated the percent change in STEMI activations in the BC versus adjusted AC (aAC) period (March 2020 to April 2021).

Results The mean monthly AMI diagnoses was 6581.86 (SD=362.43) in the BC period and 6654.79 (SD=725.76) in the AC period. No states demonstrated a negative association between monthly COVID-19 and AMI diagnoses with all sites (ρ=0.33; 95%CI=0.016-0.59), Colorado (ρ=0.48; 95%CI=0.18-0.7), Massachusetts (ρ=0.4; 95%CI=0.09-0.64), New Hampshire (ρ=0.11; 95%CI=0.1-0.65), and Pennsylvania (ρ=0.46; 95%CI=0.15-0.68) revealing positive associations. With a one-month delay applied to ACS diagnoses, Colorado (ρ=0.53; 95%CI=0.24-0.74), Massachusetts (ρ=0.34; 95%CI=0.02-0.60), and Pennsylvania (ρ=0.37; 95%CI=0.05-0.63) demonstrated positive associations. In the mixed linear model, the percent change of regional and statewide AMI diagnoses in the aAC period was negative in the first three months compared to the BC period, albeit not reaching statistical significance.

Conclusions No negative association was found between monthly statewide or aggregate COVID-19 burden and AMI diagnoses among, even with a one-month delay applied to AMI diagnoses. Contradicting previous studies, there was no observed reduction in AMI diagnoses across hospital systems after the start of the COVID-19 pandemic. This may reflect psychosocial factors such sedentarism, social distancing, or increased ED visits for chest pain; however, studies with more precise regional data are required to validate these results.